1. Technical Field
The invention relates to methods and materials involved in the production of organic products.
2. Background Information
Organic products such as lactic acid have many important industrial uses. For example, organic acids can be used to synthesize plastic materials as well as other products. To meet the increasing need for organic products, more efficient and cost effective production methods are being developed. One such method involves the use of bacteria. Specifically, certain bacteria can produce large quantities of particular organic products under certain fermentation conditions. The use of living bacteria as factories, however, is limited by the inability of the bacteria to grow as the organic product accumulates in the growth media. To circumvent such limitations, various product purification techniques have been employed during product synthesis. In addition, the use of microorganisms other than bacteria has been attempted. In fact, Saccharomyces cerevisiae, which is known to be acid tolerant, has been genetically modified in an attempt to produce lactic acid. Specifically, S. cerevisiae cells were modified by providing the cells with a bovine lactate dehydrogenase cDNA and disrupting endogenous pyruvate decarboxylase genes (PDC1, PDC5, and PDC6). While these modified S. cerevisiae cells produced some lactic acid, cell growth was suppressed leading to the conclusion that both cell growth and lactic acid production need improvement.